ELECTRONIC SHIFT LEVER SYSTEM, Diagnostic DTC:P176A87

DTC Code DTC Name
P176A87 Lost Communication with Fail Safe Signal (Gear Shift Control Module "A") Missing Message

DESCRIPTION

The shift control ECU sends SBFS (fail-safe) signals to the hybrid vehicle control ECU.

DTC No. Detection Item DTC Detection Condition Trouble Area Warning Indicate
P176A87 Lost Communication with Fail Safe Signal (Gear Shift Control Module "A") Missing Message

The SBFS (fail-safe) signals sent from the shift control ECU cannot be received by the hybrid vehicle control ECU continuously for 2 seconds or more.

(1 trip detection logic)

  • Shift control ECU

  • Hybrid vehicle control ECU

  • Wire harness or connector

  • Master Warning Light


    • Comes on

  • Multi-information Display Error Message


    • Displayed

CONFIRMATION DRIVING PATTERN

Tech Tips

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the All Readiness check procedure.

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  1. Turn the power switch on (READY) and wait for 2 minutes or more.

WIRING DIAGRAM

B004WLJE07
*a SBFS
*b Shift Control ECU
*c Hybrid Vehicle Control ECU

CAUTION / NOTICE / HINT

Note

The vehicle is equipped with a sub-battery. Therefore, ensure there is no power being supplied to the vehicle when disconnecting or reconnecting the connector of the shift control ECU and when removing or installing the shift control ECU.

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PROCEDURE


  1. CHECK SHIFT CONTROL ECU (CHECK SBFS TERMINAL WAVEFORM)


    1. B004Y49C04
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)
      *b Waveform (Fail-safe signal)

      Disconnect the hybrid vehicle control ECU connector.

    2. Connect an oscilloscope between the hybrid vehicle control ECU connector terminals specified in the table below.

    3. Turn the power switch on (IG) and measure the waveform.

      Tester Connection Condition Equipment Setting
      G92-25 (SBFS) - G92-6 (E1) Power switch on (IG) 10 V/DIV., 20 ms./DIV.

      Note

      Turning the power switch on (IG) with the connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

      Tech Tips

      The waveforms differ when the shift control ECU is malfunctioning.

    4. Turn the power switch off.

    5. Reconnect the hybrid vehicle control ECU connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HYBRID VEHICLE CONTROL ECU Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (SHIFT CONTROL ECU - HYBRID VEHICLE CONTROL ECU)


    1. Disconnect the G81 shift control ECU connector.

    2. Disconnect the G92 hybrid vehicle control ECU connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      G81-3 (SBFS) - G92-25 (SBFS) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      G81-3 (SBFS) or G92-25 (SBFS) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the G92 hybrid vehicle control ECU connector.

    5. Reconnect the G81 shift control ECU connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SHIFT CONTROL ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR